Requesting a WAKE example

I would like an example of how to use WAKE because I'm not quite sure how it's supposed to work. I'll contribute one if I can, but right now it doesn't work. Should it?

#
# Example of putting the main processor to sleep then waking it up
# via the ULP after a while
#
from esp32 import ULP
from machine import mem32
import machine

from esp32_ulp import src_to_binary

source = """\
#define RTC_CNTL_LOW_POWER_ST_REG 0x3FF480c0
#define RTC_CNTL_RDY_FOR_WAKEUP BIT(19)

entry:
        MOVE r0, 2000

loop:
        WAIT 40000  // at 8 MHz this is 5 msec, if we do this 1000 times that's 5 seconds
        SUB r0, r0, 1
        jump is_rdy_for_wakeup, eq
        jump loop


is_rdy_for_wakeup:                   // Read RTC_CNTL_RDY_FOR_WAKEUP bit
#
# This test was described in https://github.com/espressif/esp-idf/issues/8341
# See reference manual 31.19.
#
# The main issue with this is that it will hang if the main CPU wasn't in deep sleep.
#
       READ_RTC_FIELD(RTC_CNTL_LOW_POWER_ST_REG, RTC_CNTL_RDY_FOR_WAKEUP)
       AND r0, r0, 1
       JUMP is_rdy_for_wakeup, eq    // Retry until the bit is set

       WAKE                          // Trigger wake up
       HALT                          // Stop the ULP program
"""

#
# Compile the ULP code
#
binary = src_to_binary(source)

load_addr, entry_addr = 0, 0
ULP_MEM_BASE = 0x50000000
ULP_DATA_MASK = 0xffff  # ULP data is only in lower 16 bits

ulp = ULP()
ulp.load_binary(load_addr, binary)

#
# The ULP starts out asleep (halted), so set a timer to wake it
# up the first time.
#
# ulp.set_wakeup_period(0, 50000)  # use timer0, wakeup after 50.000 cycles

mem32[ULP_MEM_BASE + load_addr] = 0x1000
ulp.run(entry_addr)

print("going to sleep")

# I think this should enable ULP wakeup
mem32[ 0x3ff48038 ] = 0x200 << 10
machine.deepsleep()


#
# We won't ever reach this, because WAKE is going to cause the main
# processor to reset and start over at the beginning.
#
print("I am awake again")

Start with the Python example in the issue, especially ULP, src_to_binary, mem32, and machine.deepsleep, then inspect the repository's existing examples and documentation for WAKE usage. Determine whether the shown deep-sleep flow works and document a minimal working example, including what users should observe after WAKE triggers.